Abstract:

Objective: To explore the clinical and prognostic characteristics of delayed platelet engraftment (DPE) in patients with systemic light chain (AL) amyloidosis after autologous stem cell transplantation (ASCT). Methods: This is a retrospective study which included all the patients who received ASCT in our center from July 2010 to February 2025. These patients were divided into two groups based on whether DPE occurred or not. Patients with platelet engraftment time ≥14 days were defined as DPE. The baseline data, treatment during ASCT, complications during ASCT, and long-term prognosis between the two groups were compared. Results: A total of 382 patients with AL amyloidosis received ASCT and 56 (14.7%) developed DPE. Compared to the normal platelet engraftment (NPE) group, the DPE group had a higher proportion of heart and liver involvement, a higher renal grade 3, as well as a higher proportion of conditioning with reduced levels of melphalan. Baseline hemoglobin, platelets, and eGFR were lower, and the number of infused stem cells was also reduced. The proportion of patients with Eastern Cooperative Oncology Group (ECOG) performance status scores of 1-2 were higher in the NPE group. The neutrophil and platelet engraftment in the DPE group was later than that in the NPE group, and the proportion of platelet and red blood cell transfusions was also higher. The incidence of bleeding, arrhythmia, and acute kidney injury during transplantation was higher too. During a median follow-up of 72 months (65.5, 78.5), the overall survival rate (OS) of the DPE group was significantly lower than that of the NPE group, while there was no significant difference in the progression-free survival between the two groups. Conclusion: DPE is not uncommon in patients with AL amyloidosis undergoing ASCT treatment. AL amyloidosis patients with DPE have more severe organ involvement, poor general condition, more complications during transplantation and shorter overall survival.

Key words:

systemic light-chain amyloidosis, autologous hematopoietic stemcell transplantation, delayed platelet engraftment, CD34+ cells, hematopoietic reconstitution